Automatic telephone system



April 7, 1925. 1,532,664

5. R. SMITH ET AL AUTOMATIC TELEPHONE SYSTEM Filed Jan. 3. 1921 2 Shani-Sheet 1 g.m1-unauzn i fiwflug;

s. R. sMm-l ET AL April 7, 1925. 1,532,664

AUTOMATIC TELEPHONE SYSTEI FilQdJOM. 3, 1921 Z'SIiQQtl-Shb'i 2 Patented Apr. 7, 1925.

A'SSIG'NORS" To avrmvrarm renames ce'r/rrA NY, on oer-mace,- I'I JLI N-ors; conronnrronor -rnrliinors; I

AUEUMAIIEOJ 'rnnErnoi-in- SYSTEM.-

Applieation filedwlanirary 3, 1921." SerialNo. 434,857:

Be it knownthat we, SIDNEY REYNELL SMITH; and JOHN Savrrr, boths-ubjects of; the King; of? Great Britain and Ireland, and

5 residents of London, England,v and Liverpool, England, res-pect-ively,- have invented certain new and; useful Improvements in Automatic Telephone Systems,- of which-the following. is a specification}.

The present invention relatestoimprove ments in callingdevices for automatic tele phone-systems, of the genera-ltyp'e wherein a rotatable dial is used to produceseries of controlling in'lpulses for the autoinatie switches and the'objectof the invention is to-provide improved means for regulating the interval which elapses between-the gen (BlittlOl-LOf successive series-of" impulses.-

Reference is hore' made toi P artcnt No.

1,444,77fi'gissued to Blessi=ng-, F-eb.-1 53,1923,-

of whichthe present invention. is an my prov-emenn The feature of the Blessing,

calling device is the. provisionof anneniben adapted. to bemoved by the finger during, thesetting operation to -lock the impulse? gene-rating mechanism, for: instance,- by inserting:anobstruction inthe path of a pin,

on its equivalentprojecting. from the shaft" of the" governor so that the'fi'n 'en has to be I' removed before the impulses can be gre ner ated; I

@neof the features of the present inven tion is the provision of ii-movable member adapted to be mo dtdprevenhthef trans n'iission' ofimpu and to return slowly under thecontrolof a; dashpot5go1 is equiv alent; By arranging that the i'nova-ble member.- issct in actionimmediately after the preceding series of impulses have been tl'illiSlHll'tEtl e. by arranging; that the very commencement of the; setting operation the movable member is moved. to loclrthe impulse generating. mechanismand subse" quently is released i after a limited movement of tl e linger holddialg say the space of one a delay between succ'eeding= sets: of impulses only occurs when the time, between succeed ing sets of impulses wou-ld otherw'ise besuclr.

as to-endanger the proper; functioningofthe switching apparatus responding thereto/.

For instance, it is' fou-ndthatit is possible to set up the dial to transmit one, two, three,

re hole, it is possible toobtai'nrecalling; device which has the important-featurethat an arrangements provided for controlling and possibly four impulses in" so short' a time as to give an incorrect functioning of the exchange apparatus, but there is little or nodanger' when the dial is set up to trans mit nine, ortendigits. Previously it has been usual to add to the setting. up time whether the number to be transmitted Was large or small ;v this is obviously wasteful and bymean's ofthe present invention it possible-to arrange that only when itis ab solutely essential to the proper functioning of the exchange apparatus is a delay intro= duced. I I. v

A further feature of the present ii1vention consists of a movable member adapted to be moved at the latter end of the setting- 3 operation to prevent tlie'generation: of impulses until the movable member is restorech toits normal position. By arranging; that the movable member short circuits the inn pulse springs and, further, that itis adapt 7 5 ed-to'yieldlover. a space of tumor more fin-: gerholes itis possible to arrangethat the return of the movable member is c'ontrolled by; the samegovernor as isused-for reg-ulatingthe generation of impulses' and that a delay may. be. obtained: without increasing the size ofthe-dial. y

Further details and features of the present invention will-be best appreciated by referring. to theaccompanying. drawings in which k I Figures 1,2, andBshow one construction of calling device in whichthe'movable finger stop-efi'ectsthe lockingvof the impulse generating mechanism. Fignre l shows so front view while Figures 2 and 3 "show rear viewswith the movable finger stopintwo differentpositions: Figures Land 5 show front and rear views, respectively, of an other construction wherebyunnecessary delay between the tiansmission of successive series of impulsesis avoided; and Figures 8, 6, and 7 showinverted plan, sectional-elevation and-section on line ALB, respectively,- of a third? construction whereby while-re- 190 tainingthe features of thefirst' construction the return of the movable member by the same governor as is employed: for regulatingvthe generation of impulses.

, Referringi'to Figures '1,=2,-and 3, the r-alling device comprisesthe usual dialer-finger" hold plate ladapted to be rotated-in a clockwise direction by inserting a finger or pencil in one of the holes shown and moving up to a rigid stop. The finger hold plate 1 on being rotated winds up a spring 2 which tends to restore it to its original position. On being released, by means of the usual ratchet mechanism (not shown), the interrupter cam 3 and governor 4 are engaged with. the finger hold plate and rotate with it. The interrupter cam 3 separates the interrupt r springs 5 intermittently a number of times depending on the number opposite the hole in which the finger was first inserted, while the governor regulates the speed at which the impulses are generated so that they are most suitable for the correct operation of the automatic switches.

Such operation and construction is well known but is modified in the present construction by providing in place of a rigid stop a movable stop 6 adapted to yield until it engages with the side of the guide plate 7. The stop 6 is pivoted on the underneath side ofthe dial about the projections 8, used for regulating the tension of spring 2, by means of an annular disc 9 which is held to the rear plate 10 partly by means of the screw 11 and partly by the guide plate 7. Through the governor shaft a pin 12 is forced projecting about equally on each side and adapted to engage with the annular disc 9 except when this disc is in the position shown in Figure 2, as then the pin comes opposite a slot 13 provided in the disc 9. The operation may then be briefly described as followsz-JVhen the finger in setting up the dial comes into engagen'ient with-the finger piece 6 it carries it round through a position such as shown in Figure 3 to a stop due to the finger piece (3 engaging with the end of the guide plate 1 During this time the slot 13 in the annular disc 9 has been moved in the direction shown in Figure Now if the fii'iger is not removed, even if the finger assists, the dial cannot move backwards, because the pin 12 engages with the disc 9 and cannot rotate as this obstruction is in that; part of the gearing which runs at the highest speed and includes the wormwheel 14-. Consequently the finger must be removed before any other operation can take place. Once the finger is removed the annular disc is restored to its normal position as shown in Figure 2 by means of the spring 15 and then when it reaches this position, and not before, the pin 12 on the governor shaft is released and the finger hold plate can return, rotating with it, by means of the ratchet device, the interrupter cam 3 and the governor Obviously it is sometimes desirable to corn trol the time between successive impulses son'iewhat more positively than described in the foregoing, and for this purpose a dashpot or othrr time regulating device-nmy be employed, for controlling the return of the locking member.

Referring to Figure 5, this shows the rear view of another construction of dial which differs from the previous construction in that the annular disc 9 is cut off short at the stem 16 so that the finger piece 6 is eliminated being replaced by the usual fixed finger stop 17. On the disc 9 a leaf spring 18 is secured having one end bent in a suitable curve so as to be engaged by the locking dog 19. This locking dog 19 is usually provided for the purpose of locking the pinion 20 on the return of the finger-hold dial to its normal position and thereby preventing the further generation of impulses due to the inertia of the moving parts.

In addition to the other modifications mentioned, a dashpot 21 is provided pivoted to the plate 10 at 22 and to the disc 9 at 23. In its simplest form the dashpot may comprise a piston or rod 24 and a small cylinder 25 having therein a small aperture arranged to retard the return of the disc 9 under the control of the spring15 as will be readily appreciated. Obviously the dashpot might be replaced by an equivalent device performing the same function without departing from the spirit of the invention.

The operation is as follows A finger is inserted in one of the holes in the finger hold plate and rotated clockwise as usual; shortly after the commencement of the movement the dog 19 engages with the downturned edge of the spring 18, thereby causing the disc 9 to move against the spring 15 so that the slot- 13 is no longer under the pin 12, (Figure 2). Eventually the spring 18 engages with the end of the slot'26 in the plate 10 so that it can move no further; at this instant, the dog 19 is enabled to pass the spring 18 which is forced outwards sufficiently to permit this and the dog 19 is then carried round with the dial plate. Now obviously as soon as the dog 19 had passed the spring 18, the disc 9 is free to return to its normal position but slowly under the combined control of the spring 15 and the dashpot action of rod 24 in cylinder 25. This return is regulated so as to take up a definite interval of time corresponding to the maximum time required between the transmission of successive series of impulses. Consequently the backward rotation of the dial and the generation of impulses is rendered impossible until this time interval has elapsed. Consequently if the finger reaches the finger stop 17 before this time has elapsed, the dial will not return until it has, while if the finger reaches the finger stop 17 after this time has elapsed, the dial can immediately rotate backwards and generate impulses. The dog 19 is so shaped as to pass the leaf spring 18 readily on its return movement.

It Will he appreciated, therefore, that by thlS' construction 1t s impossible to generate SUCCGSS'HG" series of impulses Without these being separated by the correct time interval required for the system; while at the same time, no Waste-of time-nor unnecessary delay need occur. v p

Another improvement is illustrated in Figures 6, 7, and 8-," and difi ersfionr the pr'e*-- ceding? construction as will he appreciated" from thefo'llowing description". 7

Thedial plate 1 is fittedwi th a. Step2? on its under side-in place of the'do-g 19 Silo-W11" in Figure 5; toits shaft 29' is secured-f ratchet Wheel 28"; WhilehetWeen theuatch'et Wheel 28-and the plate 1i a finger piece- 3?)" is adapted to move freely about the' shaft 29.

@n tlieunderside of the'fin'ger piece30 is an arm-31 eXtendingasshown inFigur'e 6 to the-under side of the rear plate T 2: on this arm ahall or like member 32is fittedinsu'ch a manner-as to'have a" certain freedom" of movement in a radial direction only. For

instance, the-hall 32 may he slotted aindif desired be forced outwards under spring lIQIISlOH hllIS springv 1n thec'as'e of a. ball, however, 1s not essential;

Secured t'o'therear plate is a: guide p'lltt'er 33' Wh1ch serves to control and direct the position of the hall as will be" explained later. I g is hmited by means of stn ssand Ease cured to-the edge of the're'ar platelOa nd' extending into the path of the finger piece" On the-under side" of the -rearp'late a pair of contact sprin, ;s 36' and 37' are mounted;

'Phes'e' are normally separated hut tissues as thefinger piece 30 is moved fi om' 'normafpo sition they make contact tosho'rt circuit the? Suppose it isdesired to generate Ill iin pulses the operator will insert his finger in the hole in the finger'ho'ld plate 1" -oppe=- site the numeral 0 and Wi11 tlfen= move'the plate in clockwise direoeion until' it comes to a stop.- Prior tore'a'ch'mgi the-"stbpthe finger Wlll have engaged withthe finger piece *moving it" with thebah 32 and the arm 31 with its extension piece 39! The bal1= is soar-ranged that due-tUthe-monthur of the-guiding plate it isdorced into re cess iii-between theratch'et teeth; the ratchet teeth being" arranged asto p'ermit'of this at this instant. Preferably: there are the The m'ovement'o'f the fi nger' piece30 its normal position pressing against same number of ratche't teeth on the Wheel- 28; as'there are ratchet teeth-* on the crown" wheel 4'0 which is provided in=a -weh known type of dial switch for providing the one Way clutch between the finger h old plate and 7 theimpulse generatingmechanism. B'y' this m'ea-ns-an accurate" relationship between the" locationof the finger piecewith the finger ho'ld plate can-Best be assured. 7 The movement of the fingerpieoe: 30* throughth'e' arm" 3-1 andi'ts extension piece" 39"- e fl'ects the short cirouit'ing of the inter;- rupter springs b'y means of the springs 36 and 87 which close as soon; as extension piece 39'' is: moved from' engagement with 8 spring'36 subsequently the" e X-tension piece? 39 engages With pin" 38- on annular disc U and c'au'sesthis disc touot'ateuntil' the finger piece 30 engages with the stop" 35* when" everything comes:- to' rest. n p

The movement of the annular disc Ohas effected the lock-ingo'fthe governor so t" not until it returns to' i'ts'n'ormal' pcsitlion can the" finger hold plate returuz' This can only be attained by the operator removing his finger from the hold when the: disc in me'diat-ely' restores under the' control of the. spring 1 5 and' brings with" it the finger piece 302 As Will be seen, the guide plate 33 at this point is? iiirtfher' army from the ratchet Wheel so that the loa ll campa ss the ratchet tooth which would otherwise ohstru'ct the return of the finger piece: its soon' as" fillBdlSC' 9 re a'clies it's normal posit-io'n' the governo'r is rel-eased and the" finger I hold plate begins to return; At this in sthnt; however, the hallfSZ on the fii'lger piece 30* is at a con'stfricte'd part of the passage bet Ween the guide plate air? the- 0)!) ratcli'et Wheel 28* and; further; is partially lying" in a: recess between the teeth. The consequence is that the fingerpiece returns with the" finger li'old plllt e. under the control ot the governor. At the sam'etime' the" interrupter springs are being hrolteu and closed; but this is of no efi'e'ct a't tliis time" as they are short circuited by the springs 36 aind 3 7: i

In due course the fihgcr piece 30 reaches 7 p he stop 34; the extension piece 3?) breaks theshort circuit across the int'errupter springs Wl1ll0 the ball- 32 ispressed intotheenlarged space allhWe-d by theguide plate 33 a't th'is' position a-n d the e'fi eetiv'e generation of iu'ipulses' conmiences; which continues-until the stop striltes against the fin'g'erpiece 30 and hush er movementis prevented.

Pt wih b'e appreciated that-a similar ciiect Willbe produced whatever the number of impulses transmit-ted, but the number lh was taken wan-example so that it-In'ight he app'r eciated that: actually the finger-hold plateis moved tl-n-ough more-than a. complete rev olu't i'on; and further that the stop 27' pew CAS Inits this, whereas the pinion 20 would obstruct the path of the dog 19 previously used for the same purpose. Further, it will be appreciated that while generating ton impulses actually the finger hold plate moves through a distance corresponding to fourteen or even more impulses and this has been attained without appreciably increasing the size of the finger hold plate or the dial generally. Again by this construction it is possible to use the same governor as controls the. generation of impulses to regulate the return of the movable member to its normal position.

Having now particularly described and ascertain-ed the nature of our said invention, what we claim is V 1. In a calling device for automatic telephone systems, a manually operable calling dial, a finger stop limiting the movement of said dial, impulse sending mechanism operated by said dial on its return, locking means operating to delay the return of said dial and effective to introduce av minimum time interval between successive actuations of said dial, and cooperating means between the said dial and locking means whereby the delay is omitted in case the normal time interval between successive actuations of said dial exceeds the minimum. I

2. In an impulse sending device, a finger hole dial rotatable forward and back, an annular member having a resilient extension, said extension adapted to be coupled to the dial to move said member for a certain period of travel at the end of Which, it is automatically released, means for returning said member to its initial position independently of the dial, and means whereby said member delays the return of the dial.

3. The combination, in an impulse trans mitter, of a finger hole dial movable in a. clockwise and counter clockwise direction, a fixed linger stop for limiting the clockwise movement of said dial, and meansoperated during the clockwise movement of the dial for slaying the counter clockwise movement of the dial only when the clockwise movement of the dial requires less than a predetermined period of time.

4t. The combination, in an impulse transmitter of a finger hole dial movable in a clockwise and counter clockwise direction, a fixed finger stop for limiting the clockwise movem-ent of said dial, and means operated during the clockwise movement of the dial for in certain instances delaying the counter clockwise movement of the dial for a variable time dependent directly on the time consumed during the clockwise movement.

5. In a calling device, a finger hole dial capable of forward and backward movement, interrupter mechanism operated by said dial on its backward movement, an automaticallymoveable stop having normal and off normal positions, means for moving said stop off normal on the forward movement of the dial, means for delaying the return of said stop for a definite time, and means for preventing the backward movement of the dial until the stop is fully restored.

6. In an impulse sending device, a rot-atable fin 'er hole dial operable in a variable forward and backward movement, a rotatable member adapted to be automatically operated and released by the dial during its forward movement, means co-operating with said member for locking the dial against return while said member is off normal, and means for controlling the restoration of said member to delay the backward movement of the dial for a definite time.

7. In a calling device, a dial adapted to be set in accordance with the digits in a called number by forward rotation thereof, sending mechanism operated by said dial on its return rotation, and means effective only in case said dial is set in accordance with a low digit for delaying the return of the dial. V

8. In a calling device, a dial adapted to be set in accordance with the digits in a called number by forward rotation thereof, sending mechanism operated by said dial on its return rotation, means tending normally to cause the return rotation of the dial as soon as the, same is released on the completion of the setting movement, and means for automatically delaying the return of the dial only in certain instances.

9. In a calling device, sending mechanism, manually operable means for settingsaid mechanism in accordance with any digit, means normally tending to operate said mechanism as soon as the setting is completed, and means for autoniiatically delaying the operation only in case the mechanism is set for, particular digits.

10. In a calling device of the type in which the setting operationmust take place after the generation of one series of impulses to effect the generation of a new series of impulses, a linger hole dial, means 7 controlled by said dial after the cessation of one series of impulses for inserting a rigid locking obstruction in the impulse mechanism to prevent the generation of a succeeding series ofimpulses until a definite lnllll- 12. In a calling device ofthe dial type in which a setting operation must take place delaying device preventing the restoration of said rigid locking member for a predetermined period.

13. In a calling device of the dial type, impulse mechanism, adisc member for preventing the impulse mechanism from operating While said disc is in an oil normal position, means for moving said disc in an oil normal position during the setting movement of the dial, means for restoring said disc to normal to render the impulse mechanism effective, and means for delaying the restoring movement of said disc for a definite period.

1 1. In an impulse transmitting device, a finger hole dial, impulse springs, means for operating said springs, disc member in said device for delaying the operation of said springs for a definite period preceding the transmission of a series of impulses, and means controlled by said dial for rendering said disc member elfective for the purpose set forth each time the dial is operated.

15. In an impulse device, impulse mechanism, a dial for setting said mechanism in readiness to transmit impulses, a blocking member, means for operating said member during the setting movement to prevent the immediate generation of impulses, means for restoring said member, and means for delaying the restoration for a definite period.

16. In an impulse transmitting device, impulse mechanism, means including a dial for setting said mechanism in motion to transmit impulses, means comprising a blocking member controlled by the dial during the setting movement for preventing the operation of said impulse mechanism, means for restoring said blocking member to normal, and means for definitely delaying the restoring operation of said member.

17. A calling device in Which a setting operation must take place after the generation of one series of impulses to efiect the generation of a fresh series of impulses, a finger hole dial, mechanism for transmitting impulses, an auxiliary part, means controlled by the finger hole dial for interposing said auxiliary part in the mechanism to prevent the generation of a fresh series of impulses, means for automatically Withdrawing said auxiliary part, and aspeed regulating device for preventing the Withdrawal. of said part for a predetermined time.

Signed by us at Liverpool, England, this 2nd day of December, 1920.

SIDNEY REYNELL SMITH. JOHN SAVIN. Witnesses:

R. MERCER, T. H. BARNES. 

